The invention relates to an antenna.
In the state of the art, different types of antennas are known which are suitable for sending and receiving data, for example using WIFI applications.
The European patent application EP 1401050 A1 describes an internal planar antenna for small radio apparatuses. The ground plane of the planar antenna is shaped such that it improves the matching of the antenna. The shaping may be carried out by means of one or more slots in the ground plane. The slot suitably changes the electrical length of the ground plane as viewed from the short-circuit point so that the ground plane will function as a radiator in an operating band of the antenna. The planar antenna is connected via a short-circuit conductor that extends from the planar antenna to the ground plane. The planar antenna is arranged above the ground plane with a predetermined distance. Furthermore, the planar antenna comprises a feed line conductor which is guided through the ground plane to the planar antenna.
The European patent application EP 0407145 A1 describes a broad-band mobile telephone antenna which comprises a first conductive circular plate and a second conductive circular plate. The first plate is located above and in parallel to the second plate. The diameter of the second plate is equal to or larger than that of the first plate. The second plate is used as a ground plate which is attached to a body of an automobile. A short-circuit rod for matching an impedance between the first plate and the second plate is used as an antenna and a coaxial feeder cable for the antenna is connected between the first and the second plate. An upper end of a core rod is connected to the first plate at the substantial center thereof. A low end of the core rod is extended towards an opening formed in the substantial center of the second plate. The opening is connected to a connector which is placed inside the automobile through an opening formed in the body. The connector connects the core rod and the coaxial cable which is connected to a transmitter/receiver of a mobile telephone system. The inner conductive wire of the coaxial cable is connected to the core rod and the outer conductive sheet is connected to the ground plate.